However much it is played down, there can be little doubt that one of the reasons Rafael Benítez was appointed Chelsea's interim first-team manager last November was to get the best out of Fernando Torres, having done just that when the pair were at Liverpool. Yet there is now the increasing sense that it will be on Benítez's watch that the striker's torturous spell at the club finally ends.

That was certainly the strongest conclusion to be drawn from this tie, during which Torres could only watch from the substitutes' bench as Demba Ba shone on his debut for Chelsea following his £7m arrival from Newcastle on Friday. The Senegal forward required only 61 minutes to register his first two goals for the European champions, which rather put into context the 14 games, or 732 minutes to be precise, Torres needed to get just one after his £50m transfer from Anfield two years ago. Southampton, it is fair to say, were not the only ones left feeling humiliated at St Mary's.

"For me it's a great opportunity to manage two different strikers," said Benítez as he stressed that Ba's stellar start to his Chelsea career did not spell the end for Torres. "It will be good for the team also because both players can score goals and, if they are fresh, they can make a difference."

"Fresh" was a word Benítez used on more than one occasion to defend Torres, pointing out that his compatriot required rejuvenation having been Chelsea's sole striker for the bulk of this campaign, starting 31 of Chelsea's 33 competitive games and scoring 14 times. But what boded particularly badly for the player here was Ba's overall contribution.

The 27-year-old was always on the move, making runs that gave his team-mates a regular outlet and in scoring his two goals – the first of which got the FA Cup holders on level terms after they had fallen behind to Jay Rodriguez's opener, while the second increased their lead to 4-1 – showed muscular determination. Quite simply he was everything Torres has not been for some time.

"He [Ba] is good on the ball, good in the air and we have seen he can be a threat," added Benítez. "He will be a good addition as now we have different options depending on whether we want to play one way or another. Also, if we want to play with two strikers, we can."

Asked if he would be happy to play alongside Torres, Ba gave a less than enthusiastic reply – "If I have to play with him, I'll play" – and the general feeling is that is a scenario unlikely to take great shape at Stamford Bridge. This is principally because Benítez prefers his teams to have a lone focal point and also because of the effect that reverting to a two-man attack would have on Chelsea's midfield, particularly on Juan Mata, who was once again outstanding here in a roaming role just off the striker.

The Spaniard set up Ba's first goal on 35 minutes after skilfully moving into the Southampton area and lifting the ball over Artur Boruc, and then provided the cross for Branislav Ivanovic to make it 3-1. Either side of that goal, Victor Moses and Ba, again, also scored as Chelsea steamrollered Nigel Adkins' side.

The seal on Chelsea's third-round win was applied by Frank Lampard's 83rd-minute penalty, which brought the midfielder level with Kerry Dixon as Chelsea's second all-time high scorer with 193 goals, nine behind Bobby Tambling. Reports emerged later that the club were in discussions with Lampard's representatives over a fresh contract but the 34-year-old's agent, Steve Kutner, said he had been told by Chelsea that no extension will be offered to his client.

When Lampard leaves at the end of the season he may well be joined at the exit door by a player the club spent £50m to purchase. Torres was once the great hope of the Stamford Bridge supporters; now he can only watch as they revel in the brilliance of Ba.

Isn't Mr Nakrani's article on his comparison between Demba Ba and Fernando Torres too early ? Thers's a match today, Jan 9 2013, between Chelsea and Swansea. Let's see how Demaba Ba fares. I am a fan of Chelsea. I like the likes of Terry, Lampard, Hazard, Oscar, Peter the goal keeper, David Luiz , Fernado Torres , to name just a few among them all players. Of course I like the way Ba palyed the first time with Chelsea because I want Chesea to win ( fair and square ) but isn't it too early to compare Ba and Torres after Ba's just one game with Chelsea ? Wasn't it Torres who helped Chelsea win the European championship ?
T. Newin